I checked out Brendan Coyle's 4th Floor Studio earlier this evening. One of the cooler, more useful real-world applications of virtual reality is how it impacts architectural visualization. Brendan, for example, takes the dimensions of prospective apartments and models them in 3D to ensure it is a viable space for him and his furniture. He modeled his 4th floor studio apartment using a combination of 3D scanning and hand modeling and made it compatible with the DK2. Without having to leave my house, I was able to better determine that I would feel comfortable living in a place of that size (but only if I am by myself) than I would have just looking at pictures.

I can already envision a fancy real-estate site that offers VR demos of its various listings.